<?php
/*
Usage

Save the above file as SimpleImage.php and take a look at the following examples of how to use the script.

The first example below will load a file named picture.jpg resize it to 250 pixels wide and 400 pixels high and resave it as picture2.jpg

<?php
   $image = new ImageService();
   $image->load('picture.jpg');
   $image->resize(250,400);
   $image->save('picture2.jpg');
?>
If you want to resize to a specifed width but keep the dimensions ratio the same then the script can work out the required height for you, just use the resizeToWidth function.

<?php
   $image = new ImageService();
   $image->load('picture.jpg');
   $image->resizeToWidth(250);
   $image->save('picture2.jpg');
?>
You may wish to scale an image to a specified percentage like the following which will resize the image to 50% of its original width and height

<?php
   $image = new ImageService();
   $image->load('picture.jpg');
   $image->scale(50);
   $image->save('picture2.jpg');
?>
You can of course do more than one thing at once. The following example will create two new images with heights of 200 pixels and 500 pixels

<?php
   $image = new ImageService();
   $image->load('picture.jpg');
   $image->resizeToHeight(500);
   $image->save('picture2.jpg');
   $image->resizeToHeight(200);
   $image->save('picture3.jpg');
?>
The output function lets you output the image straight to the browser without having to save the file. Its useful for on the fly thumbnail generation

<?php
   header('Content-Type: image/jpeg');
   $image = new ImageService();
   $image->load('picture.jpg');
   $image->resizeToWidth(150);
   $image->output();
?>
 */ 

class ImageService {
   
   var $image;
   var $image_type;
	
   const SMALL = 'thumbnail';
   
   function load($filename) {
      $image_info = getimagesize($filename);
      $this->image_type = $image_info[2];
      if( $this->image_type == IMAGETYPE_JPEG ) {
         $this->image = imagecreatefromjpeg($filename);
      } elseif( $this->image_type == IMAGETYPE_GIF ) {
         $this->image = imagecreatefromgif($filename);
      } elseif( $this->image_type == IMAGETYPE_PNG ) {
         $this->image = imagecreatefrompng($filename);
      }
   }
   function save($filename, $image_type=IMAGETYPE_JPEG, $compression=75, $permissions=null) {
      if( $image_type == IMAGETYPE_JPEG ) {
         imagejpeg($this->image,$filename,$compression);
      } elseif( $image_type == IMAGETYPE_GIF ) {
         imagegif($this->image,$filename);         
      } elseif( $image_type == IMAGETYPE_PNG ) {
         imagepng($this->image,$filename);
      }   
      if( $permissions != null) {
         chmod($filename,$permissions);
      }
   }
   function output($image_type=IMAGETYPE_JPEG) {
      if( $image_type == IMAGETYPE_JPEG ) {
         imagejpeg($this->image);
      } elseif( $image_type == IMAGETYPE_GIF ) {
         imagegif($this->image);         
      } elseif( $image_type == IMAGETYPE_PNG ) {
         imagepng($this->image);
      }   
   }
   function getWidth() {
      return imagesx($this->image);
   }
   function getHeight() {
      return imagesy($this->image);
   }
   function resizeToHeight($height) {
      $ratio = $height / $this->getHeight();
      $width = $this->getWidth() * $ratio;
      $this->resize($width,$height);
   }
   function resizeToWidth($width) {
      $ratio = $width / $this->getWidth();
      $height = $this->getheight() * $ratio;
      $this->resize($width,$height);
   }
   function scale($scale) {
      $width = $this->getWidth() * $scale/100;
      $height = $this->getheight() * $scale/100; 
      $this->resize($width,$height);
   }
   function resize($width,$height) {
      $new_image = imagecreatetruecolor($width, $height);
      imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
      $this->image = $new_image;   
   }      
}
?>